Rainbow trout in unexplored Patagonia

Ben Etridge travels to a largely unexplored corner of Argentinian Patagonia, where two brothers have unearthed a true pocket of paradise.

If I told you I'd found paradise in Argentina, you'd likely ignore me. If I described a verdant desert where all the fish were huge, the scenery stunning and the water varied, you might think it mere fishy tales. If I told you a new destination had emerged, you might indicate that fishermen have been fishing Argentinian Patagonia for decades – surely they knew where all the fishing is? But remember that the Americas are the new world, a land where corners of paradise are still to be found. And here, in the depths of Santa Cruz province, the Trochine twins have done just that, with a new adrenaline-filled fishery.

Three years ago I was fishing in the province of Chubut, one of the six that make up Patagonia. My guides for the four days on the river were Alexander and Nico Trochine. Twins by birth and of Russian/Argentinian/French heritage, these boys exemplify a new attitude to trout fishing and guiding in Patagonia. At the age of 18, they were the youngest people ever endorsed to operate in the guide programme at Villa Angostura, and their progressive attitude to conservation and handling of the fly fishing in the area is a force for the future.

Not content with working on the rivers in Bariloche, the Rio Grande, Bolivia or the summers in Iceland, they went looking for a new and almost perfect destination in the wilderness of Santa Cruz province. On the back-side of the meseta that holds Lago Strobel – aka Jurassic Lake – they found that a river flowed fast and clear from Lago Quiroga, a very similar lake in the same system. Here, big rainbow trout were migrating down the river in search of spawning grounds. They sight-fished to 10 – 15lb fish. And the more they looked the more they found. A good quantity of these fish had moved down the river, the Rio Capitán, crossing waterfalls and becoming resident in its middle and lower sections.

The fishing here divides itself perfectly in two. On one hand you have the outlet to the lake where the big heavy rainbows lumber their way into the river to fight and fin in the current of the Rio Capitán's uppermost pools. On the other hand, you have a fishery of hardcore pocket water where holding nymphs and streamers long enough to induce a take would test the most ardent of trout-heads. But that wasn't quite it. They also found a spring creek roughly 7km in length, two other smaller lakes or lagunasand a classic, working estancia laced with rugged charm and the sweet face of Argentinian hospitality.

It is late November, early season in Patagonia, and the wind is rattling our 4x4 as we drive from the tourist hub of El Calafate to Kooi Noom. The first time I'd visited this estancia, three years previously, I'd witnessed Alex hooking a beautiful 10lb cock fish from a pool on the Capitán River. This time I was coming for a week. It was the second full season that Kooi Noom was in operation and Nico and Alex were enthusiastic about the possibilities.

“There is still so much to learn about the behaviour of these fish,”Alex tells me as we pass a herd of guanacos (think small humpless camels) lazily milling around the edge of the epic Ruta 40. “Yet we don't know if the fish run out of the river and towards the Atlantic or stay in the river. We know some of the fish that migrate cannot return and become resident in the river. They slim down, lose that lake weight, but gain condition and become really good fighters.”

It's day one and we're looking at the outlet of Lago Quiroga as the Capitán River begins its journey towards the valley below. The pools here are like funnels, starting wide then closing to a narrow tail with a shelf and clearly defined channel. The massive migratory trout can be seen holding in the current, at times fighting for space, chasing each other up onto the muddy flat at the side of the river, fins out of the water, twisting and cruising before slinking back into the channel. At first I struggle with the casts – the wind today is blowing a refreshing 60km/h up the valley, whipping the tussocks of fine blonde and green Patagonian grass horizontal. After a number of inadequate casts I get some feeling into the streamer. Alex is perched above me on a steep bank, spotting and directing the action for me as the ripple makes seeing the fish from my angle really tough. Initially we're using a thinly dressed black and red coloured fly, and afterwards try white.

“Strip, strip. Stop. Now strip again. La tomó! la tomó! (he took it, he took it!),” he wails and bang, the line goes solid, instantaneously ripping through my fingers until it's on the reel which zings to life and starts to work against the maddened fish. Adrenaline surges as I try to focus on what the hell is going on. It's pure experience this, I can't hear or appreciate much else apart from the bursts of speed of the fish. It bolts to the other side before whooshing 30 yards upstream in a straight line, twisting and rolling in the deep to throw the fly.

We decided later in the day that a little less wind would have been beneficial. Here you have to fight the fish with rod tips down and bent in the direction the wind is blowing, hence not adding more breaking strain to the leader or hook setting. At Kooi Noom the learning curve is steep and abrasive.

It's almost 40 years since Bruce Chatwin penned his episodic masterpiece, In Patagonia. I wonder what has changed since then or if, actually, Patagonia is a land that doesn't change, or can't. It's such a visceral experience just being there that perhaps the only thing that can change are the people that tread it. To wake up everyday and walk out, braced and ready to fling whatever flies you've got to big trout, is special – the days float by, your thoughts muted by wind and fishing. Each day brings small, new details – the position of fish in eddying water; the type of fly for the size of stream – they all fit together like a jigsaw puzzle as the week passes.

This place has remained here and untouched for centuries, and for a person to step into it, to put a foot on its timeline, is quite humbling. The slopes of the hillsides are littered with seams of massive fossilized oyster shells, almost a foot long and bleached white, remnants of an ancient seabed. In other parts of the estancia you can find pre-Columbian arrowheads and stone tools, evidence of a more recent history.

Riding in the ATV back to the estancia we were fighting the wind but in awe of the scenery. Hares run across the road, flushed from the early summer brush. Guanacos lope over the hillocks, condors sweep around above your head as you fish, the whites of their undersides in stark contrast with the black ridges in the distance, and Magellan geese and pink flamingos hang in small groups and tear away at the first sign of people.

Day three sees us fishing smaller flies in the middle section of the Rio Capitán. Some of the fish here are the migrating rainbows, others are resident fish. It's pocket water like you have never seen before – a precipitous river tumbling and carving its way through the Patagonian steppe, around huge prehistoric stones, under bends and along cavernous ravines.

The migrating fish are holding in the slack water; some behind boulders, others tucked in close to the bankside. They aren't easy to hook for two reasons: firstly their behavior is erratic because they're spawning, and secondly the current is impressively strong. The mending of your line here is crucial and has to be precise to hold a nymph in a pocket for long enough to attract any interest. We were mending huge loops to keep flies steady. At one point I saw my Brazilian friend Luciano use a boulder as an instrument for the line. By throwing a loop onto it he was gaining extra seconds of holding on the opposite side of the stream.

The resident rainbows have a different character. These are the fish you hook but don't see. On various occasions we'd be sight-casting to a big shadow in a pocket when a resident fish would come out of nowhere, drive toward the attractor pattern and hammer it. Having spent more than a season in the river, they were lithe and silvery creatures that fought hard, ran downstream on multiple occasions and had our pulses racing. At Kooi Noom you can be very sure that nearly all the fish you aim for have never before seen a fly.

Anglers the world over want big fish on small and unknown streams. For me, it is here that I have found my ideal, alongside flowering desert bulbs and strong Argentinian yerba mate. It was what I'd come to expect of Kooi Noom – as tough and as rewarding as you can find – hard on the legs but accessible, sometimes the weather was hot and sheltered and other times, on turning a corner, the wind cut through your clothing.

“Big fish, small rivers, hard fishing in pocket water, lake fishing, spring creeks, consistent water levels because we are close to Chile – it has pretty much all of the aspects needed to be a world class destination,”Alex told me excitedly. “Sometimes we even have snow up here in mid season. Mid season!” he reiterates with a smile.

These are combinations that are very hard to find, even in Argentina.

Alex and Nico have an opportunity to start at the beginning, keep things natural and make sure the wildlife stays and the fish aren't put under too much pressure. Indeed, the twins' attitude to conservation and slow, sustainable development of the destination is enthusing.

On my finals day's fishing, we took a trip to the lower section of a creek called the Tavia – a sinuous piece of water bubbling and cutting its way along grassy and sandy slopes littered again with fossilised oysters. This 3km bottom section that runs towards the estancia buildings is a spring creek fanatic's dream – a Tolkienesque vision – both impressively beautiful and full of good-sized rainbow trout.

Curve after pool after riffle contained good rainbows and our Brazilian friend again topped the chart with a stunning 4lb specimen. After the hard fishing had been done and we'd sated ourselves on the bigger fish, Alex and I stayed behind to look closer and detail some of the area. We filmed in small ponds in the matted wet vegetation and found a myriad of invertebrate life. Scuds in green, blue, orange and red whizzed around in the footage when we played it back. We saw leeches, caddis larvae and even found a seam of charcoal at the bottom of the creek, a possible indication of its richness. We proceeded with an attempt at gauging the biomass of the river by fishing a pool hard for all the fish we could, then multiplying it by the river's distance. Absorbing stuff.

Kooi Noom is translated as ‘the fish path' in the native Tehuelpe language. These Indians didn't survive to find us fishing the waters at Kooi Noom, but their historical narrative remains accurate – the Trochine brothers have found and realised a new Patagonian paradise.